Absasivbs



Ill

Patented Get. 9, i928.

' ."c I! n NW a ra U l d itsa, .a are; at

CARL ADOLIHIE KLEIN, BEE/15513011711, AIIID RUBER.

SKIRVIFETG 153331011710", F JQONDUN,

ENGLAND.

MANUFACTURE O}? GLASS, SAND, G11 ILZENT PliPEllzt, CLGTT-i, AND ABRASIVEE".

N0 Drawing. Application filed Uctobcr 1325, Se

The object of this invention is to provide an improved process for the manufacture of that class of glass, sand or flint paper, emery cloth, and like abrasives, which are Waterproof so that they can be used on damp or Wet surfaces Without being; allected by the moisture.

The invention. consists in a series of operations which enable the rnaiultacture to be carried on in a much more practical and commercial manner than by previously known processes.

The invention will be described as lpplltfil to the manufacture of Wat 'proot' sand paper, and in this case it is pretcrred to run aper forming the base from a reel. trom which it passes (at 11' it desired being; printed on the back) into a bath of linseed oil which is rept at a temperature oi at least 100 C. small proportion (say about 0.5 per cent) of paintfin or other suitable was is added to the linseed oil bath, to increase the Waterproofing effect.

From this bath the paper preferably passes between a pair of pressure rollers to remove any surplus of the water-proofing; material, and which are also kept heated to 100 C. or over.

It may then be rewound into reel form, or pass at once direct to a table or series of hot plates or rollers kept at a temperature of 100 C. or over, and While passing over this table or series oihot plates or rollers the adhesive employed to secure the abrasive to the paper is applied in any suitable manner. This adhesive, which consists ot a. mixture of a drying; oil (such as linseed oil or tnngoil) with a gum (such as dammar or copal) or synthetic resin, is heated to over 100 C. and applied to the paper While at this item perature.

i The following is an example of a suitable composition tor this adhesive, viz:

Parts by weight. Linseed or tung oil 30 Dammar or copal gum 10 rial No. 3,438, and in Great Britain August 26, 1925.

hesive is applied, according to common practi e, aiter which the sheet abrasive is rebalq-rd (at a ten'iperature 01 over 100 C.)

and the paper will then be. ready for use.

".lhe process above described may be modilied by the addition, to the adhesive composition above described, ot' a small proportion (tor instance from 2 to 5 per cent) oi parafiin or other suitable Wax. In this case the paper, after passing from the table or hot plates or rollers wh-zre the adhesive is appl'ed, next chilled, utter which the abrasive is applied. The paper thus coated passes between hotrollers to press the abrasive down into the warmed adhesive composition, alter which it is halted at at least C. as bei'ore, but the second or sizing coating' of adhesive and the subsequent rebaiting will not be necessary.

The various baking operations above relerrcd to may be carried out in an oven or other suitable heating apparatus, and it Will be found that the operation will be improved in many cases it a current of heated air is caused to pass therethrough by any suitable means.

It Will be obvious that by the use of the process above described the employment of volatile thinners in the waterproofing and adhesive materials is obviated, With the avoidance of the risk 01 fire and danger to Workers from the inhalation of the vapours of such volatile thinners.

What We claim and desire to secure by Letters Patent is 1. A process for the manufacture of waterproof sheet abrasive material. consisting in Waterproofing the base by pa ssing it through abath of linseed oil containing a small pro portion of a suitable Wax and kept at a temperature oil? at least 100 C.; removing any surplus by means oi? pressure rollers also kept heated to 100 C. or over; applying the adh esive consisting of a mixture oi? a drying oil With a synthetic resin also at a temperature oil over 100 6.; applying the abrasivematerial to the base thus prepared and baking at a temperature of over 100 (1; and applying a second coating of adhesive and rebale inn: also at a temperature of over 100 C.

2. A process for the manufacture of waterproof sheet abrasive material (insisting in Waterproofin the base by pass n it hrough a bath oft linseed oil contai'i ll pro ill) proportion of 30 parts by weight of oil to 10 parts by Weight of resin also at a temperature of over 100 C; applying the abrasive ma terial to the base thus prepared and baking at a temperature of over 100 (1; and applying a second coating: of adhesive and rebaking also at a temperature of over-100 C.

3. A process for the manufacture of Waterproof sheet abrasive material consisting in Waterproofing the base by passing it through a bath of linseed. oil containing a small proportion of a suitable an; and kept at a temperat-iiire of at least 100 C; removing any surplus by means o't pressure rollers also kept heated to 100 C. or over: applying the adhesive consisting; of a mixture of a drying oil with a synthetie resin and a small proportion of paraffin or other suitable WHX also at a temperature or" over 100 0.; drilling the base thus prepared and applying; the al r: sive; passing the material between hot rollers to press the abrasive into the adhesive composition, and baking at a temperature of: 100 C. or over.

at. A process for the u'umul acture ot waterproof sheet aorasive material eonsistiua in Waterproofing the base by passingit through a bath of linseed oil coi'it'ainiiuy a small proportion of a suitable wax and lcept at a temperature 01 at least 100 (1.; removing any surplus by means of pressure rol ers also kept heated to 100 C. or over; applyiur.- the adhesive consisting: of a ll'llfitlllt, at a drying: oil with a guru and a small proportion of paratlin or other iitable wax also at a teuiperature of over 100 1.: chilling the base thus prepared and applying); the abrasive: passing the material between hot rollers to press the abrasive into the adhesive compositioiu and. baking; at a temperature of 100 C. or over.

In Witness whereof We a t'liic our signatures iilll i iillOLPl-TE ltlililll. ROBERT SKIRVING llllOlYFl. 

